@supports (display: grid) {
  @media (min-width: 992px) {
    .site-grid {
      margin: 30px;
      grid-template-columns: [full-start] minmax(0,0fr) [main-start] minmax(0,16rem) minmax(0,110rem) minmax(0,110rem) minmax(0,16rem) [main-end] minmax(0,0fr) [full-end]
    }
  }
}

.clm {
    margin-left: 20px;
    margin-right: 20px;
}

.grid-child {
  display: -webkit-box;
  display: -ms-flexbox;
  display: flex;
  width: 100%;
  max-width: 10000px;
  margin-right: auto;
  margin-left: auto;
}